Month: March 2011

I am building an EJB Singleton that generates and maintains data that I want accessible to multple clients. Since the data is not based on any client interaction but based on the status of a single server-side application I went with an EJB Singleton.

When attempting to invoke a method via the Remote interface on the bean instance from a servlet in a separate .war which was returning a LinkedList of a custom Object that I wrote, I was getting the following error:

2011-03-15 13:17:59,232 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/DocumentRoot].[ServletClass]] (http-localhost%2F127.0.0.1-8080-3) Servlet.service() for servlet ServletClass threw exception: java.lang.reflect.UndeclaredThrowableException
       at $Proxy236.ejbRemoteMethod(Unknown Source)    at ServletClass.doGet(ServletClass.java:52) [:]
       at javax.servlet.http.HttpServlet.service(HttpServlet.java:734) [:1.0.0.Final]
       at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) [:1.0.0.Final]
       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:324) [:6.0.0.Final]
       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242) [:6.0.0.Final]
       at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [:6.0.0.Final]
       at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) [:6.0.0.Final]
       at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:181) [:6.0.0.Final]
       at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.event(CatalinaContext.java:285) [:1.1.0.Final]
       at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.invoke(CatalinaContext.java:261) [:1.1.0.Final]
       at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:88) [:6.0.0.Final]
       at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:100) [:6.0.0.Final]
       at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) [:6.0.0.Final]
       at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [:6.0.0.Final]
       at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158) [:6.0.0.Final]
       at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [:6.0.0.Final]
       at org.jboss.web.tomcat.service.request.ActiveRequestResponseCacheValve.invoke(ActiveRequestResponseCacheValve.java:53) [:6.0.0.Final]
       at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:362) [:6.0.0.Final]
       at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [:6.0.0.Final]
       at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:654) [:6.0.0.Final]
       at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:951) [:6.0.0.Final]
       at java.lang.Thread.run(Thread.java:636) [:1.6.0_17]
Caused by: java.io.IOException
       at org.jboss.serial.persister.RegularObjectPersister.readSlotWithMethod(RegularObjectPersister.java:107) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.defaultRead(RegularObjectPersister.java:269) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.readData(RegularObjectPersister.java:241) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.readObjectDescriptionFromStreaming(ObjectDescriptorFactory.java:412) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.objectFromDescription(ObjectDescriptorFactory.java:82) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.DataContainer$DataContainerInput.readObject(DataContainer.java:845) [:6.0.0.Final]
       at org.jboss.serial.io.MarshalledObjectForLocalCalls.get(MarshalledObjectForLocalCalls.java:60) [:6.0.0.Final]
       at org.jboss.ejb3.remoting.IsLocalInterceptor.marshallOrPass(IsLocalInterceptor.java:117) [:1.7.17]
       at org.jboss.ejb3.remoting.IsLocalInterceptor.invokeLocal(IsLocalInterceptor.java:91) [:1.7.17]
       at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:75) [:1.7.17]
       at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
       at org.jboss.aspects.remoting.PojiProxy.invoke(PojiProxy.java:62) [:1.0.1.GA]
       at $Proxy181.invoke(Unknown Source)    at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:185) [:1.0.11]
       … 23 more
Caused by: java.lang.reflect.InvocationTargetException
       at sun.reflect.GeneratedMethodAccessor409.invoke(Unknown Source) [:1.6.0_17]
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [:1.6.0_17]
       at java.lang.reflect.Method.invoke(Method.java:616) [:1.6.0_17]
       at org.jboss.serial.persister.RegularObjectPersister.readSlotWithMethod(RegularObjectPersister.java:103) [:6.0.0.Final]
       … 36 more
Caused by: java.io.IOException
       at org.jboss.serial.persister.RegularObjectPersister.readSlotWithMethod(RegularObjectPersister.java:107) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.defaultRead(RegularObjectPersister.java:269) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.readData(RegularObjectPersister.java:241) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.readObjectDescriptionFromStreaming(ObjectDescriptorFactory.java:412) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.objectFromDescription(ObjectDescriptorFactory.java:82) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.DataContainer$DataContainerInput.readObject(DataContainer.java:845) [:6.0.0.Final]
       at org.jboss.serial.persister.ObjectInputStreamProxy.readObjectOverride(ObjectInputStreamProxy.java:68) [:6.0.0.Final]
       at java.io.ObjectInputStream.readObject(ObjectInputStream.java:362) [:1.6.0_17]
       at java.util.HashMap.readObject(HashMap.java:1047) [:1.6.0_17]
       … 40 more
Caused by: java.lang.reflect.InvocationTargetException
       at sun.reflect.GeneratedMethodAccessor408.invoke(Unknown Source) [:1.6.0_17]
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [:1.6.0_17]
       at java.lang.reflect.Method.invoke(Method.java:616) [:1.6.0_17]
       at org.jboss.serial.persister.RegularObjectPersister.readSlotWithMethod(RegularObjectPersister.java:103) [:6.0.0.Final]
       … 48 more
Caused by: org.jboss.serial.exception.SerializationException: Could not create instance of org.jboss.logmanager.log4j.BridgeLogger – org.jboss.logmanager.log4j.BridgeLogger
       at org.jboss.serial.classmetamodel.ClassMetaData.newInstance(ClassMetaData.java:342) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.readData(RegularObjectPersister.java:239) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.readObjectDescriptionFromStreaming(ObjectDescriptorFactory.java:412) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.objectFromDescription(ObjectDescriptorFactory.java:82) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.DataContainer$DataContainerInput.readObject(DataContainer.java:845) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.readSlotWithFields(RegularObjectPersister.java:353) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.defaultRead(RegularObjectPersister.java:273) [:6.0.0.Final]
       at org.jboss.serial.persister.RegularObjectPersister.readData(RegularObjectPersister.java:241) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.readObjectDescriptionFromStreaming(ObjectDescriptorFactory.java:412) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.objectFromDescription(ObjectDescriptorFactory.java:82) [:6.0.0.Final]
       at org.jboss.serial.objectmetamodel.DataContainer$DataContainerInput.readObject(DataContainer.java:845) [:6.0.0.Final]
       at org.jboss.serial.persister.ObjectInputStreamProxy.readObjectOverride(ObjectInputStreamProxy.java:68) [:6.0.0.Final]
       at java.io.ObjectInputStream.readObject(ObjectInputStream.java:362) [:1.6.0_17]
       at java.util.LinkedList.readObject(LinkedList.java:981) [:1.6.0_17]
       … 52 more
Caused by: java.lang.InstantiationException: org.jboss.logmanager.log4j.BridgeLogger
       at java.lang.Class.newInstance0(Class.java:357) [:1.6.0_17]
       at java.lang.Class.newInstance(Class.java:325) [:1.6.0_17]
       at org.jboss.serial.classmetamodel.ClassMetaData.newInstance(ClassMetaData.java:334) [:6.0.0.Final]
       … 65 more

After some fairly extensive experimentation I determined that the error was the result of a composed instance org.apache.log4j.Logger. Even though I included the same version of the log4.jar file in both the ejb.jar and the .war file it seems as though the class loader was having problems marshalling the Logger instance.

Had I the time to fully get it sorted out so that I could use the Logger instance in the custom class that I was returning I would, but alas . . . the rest of the project awaits.

Let’s say you have a server who’s IP address or domain name changes on which you have a Subversion repository. Furthermore, you have checked out the copy over an ssh connection using svn+ssh.

If you have checked-out copies of your repo, and the path to the repo on the file system hasn’t changed, but only the IP or domain name has changed you need to issue the following command in the root of your checked out copy:

svn switch –relocate svn+ssh://user@old.domain/ svn+ssh://user@new.domain/

Authenticate to the new machine.

svn update

Authenticate again.

Done.

I am currently working with virtual machines via Vmware vSphere on a Windows 2008 server. Initially I was unable to get the guest to render full screen and did not have all of the screen resolutions that I would have thought I should. What I was trying to do was have the guest Linux (in this case RedHat Enterprise Linux 6) run full-screen. It was not as straight forward as setting the screen resolution in the VM guest settings dialog.

After much trial and error the way to do it is to crank up the amount of ram allocated for the virtual video card. The guest will then have enough resources to render at full screen and you will have a wide array of screen resolution choices.

If you have installed the latest and greatest JBossAS tools into eclipse, try using the following version instead:

?2.2.0.v20110216-175

It seems as though there are some problems with the latest and greatest that causes compilation problems.